Forward CG Experience

It's my understanding that after Pappy Gunn had modified a B-25 for
straffing, with six 50 Cal Brownings in the nose and a 75mm field howitzer
under the floor of the cockpit, and had used it very successfully against
Japanese shipping, North American sent an engineer out to see what this
lunatic was doing. After looking over Gunn's field modification he just
shook his head and asked "Where the hell is the center of gravity?" Gunn
just shrugged and told him "Aw, we threw that out to save weight." The
engineer went home and North American started mass producing a properly
engineered variant of Gunn's cludge, the B-25G.

--
Bob (Chief Pilot, White Knuckle Airways)


"Corky Scott" wrote in message
...
On Fri, 14 Nov 2003 14:42:39 GMT, "Jay Honeck"
wrote:

Recently we flew with a friend who weighs over 320 pounds. With he and
I
in the front seat, and just Mary in the back, we were at the very forward
limits of the allowable CG.

Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

Jay, with your indulgence, a little military history that is on your
post's topic.

During the dark days following Pearl Harbor and the invasion of the
Phillipine Islands, a highly practical and inveterate ex Navy pilot
scrounger by the name of Paul (later called Pappy) Gunn ran a rough
house airline out of the Phillipines called PAL (Philipine Air Lines).
He his airplanes were requisitioned by the army and Pappy had various
hair raising flights and encounters with Japanese aircraft and anti
aircraft fire from both sides before he wound up in Australia and then
Port Moresby.

Cutting out a lot of his story, he ended up in charge of a provisional
transport squadron and offloaded some A-20's that had been assigned
him. He discovered that they had arrived without any machine guns.
His combat experience to date had convinced him of the need for a LOT
of forward fire power to keep the enemy's heads down on the run in to
the target so he began modifying them.

He plated over the bombardier's position and installed a row of four
50 caliber machine guns in the nose, plus two more in blisters
alongside the cockpit for a total of six forward firing machine guns.

With the machine guns, internal bracing and ammo cans and ammo, the
fully loaded A-20 was seriously nose heavy (you wondered when I'd get
to the subject?) His first takeoff, apparently wasn't. He could not
lift the nose to get airborn.

So he relocated the two machine guns in side blisters, moving them
back behind the cockpit.

At this time Gunn met up with George Kenney, who arrived in the
theater with a notion about low level attacks utilizing some parachute
equipped fragmentation bombs he'd developed, which would slow their
descent to allow the bomber to move out of danger from an explosion
once the bomb was dropped.

He saw what Gunn was doing and immediately liked the concept. He
yanked Pappy from his command in the transport squadron and placed him
in charge of modifying more attack bombers.

The A-20's were immediately extremely effective, but Pappy was unhappy
with their performance, feeling that he needed a bigger bomber with
more capacity. Enter the B-25 strafer.

I've got to stop, I could go on about this for a while longer. ;-)

Corky Scott

Bob

NA turned out 406 B-25G models with one 75mm and two 50 cal in the
nose.

Navigator/Cannoneer loaded the single shot canon. Bird carried 15
rounds which weighed 15 lbs each.

NA built cannon birds started arriving Brisbane in 1943.

Gun was a 75 MM CANNON, Army type M4 (not a howitzer). Gun was
descended from the French 75 of WWI fame.

Follow on was the B-25H which had the 75 mm cannon plus eight 50 cals
in nose (all fired by pilot)
..
The only bird I know of that uses a bigger gun (105 mm) is the C-130,
Spector, Gun Ship.

Not trying to take anything away from Gunn story, just giving
additional data on the NA built Cannon equiped birds.


Big John


On Fri, 14 Nov 2003 20:46:24 -0500, "Bob Chilcoat"
wrote:

It's my understanding that after Pappy Gunn had modified a B-25 for
straffing, with six 50 Cal Brownings in the nose and a 75mm field howitzer
under the floor of the cockpit, and had used it very successfully against
Japanese shipping, North American sent an engineer out to see what this
lunatic was doing. After looking over Gunn's field modification he just
shook his head and asked "Where the hell is the center of gravity?" Gunn
just shrugged and told him "Aw, we threw that out to save weight." The
engineer went home and North American started mass producing a properly
engineered variant of Gunn's cludge, the B-25G.

On Fri, 14 Nov 2003 20:46:24 -0500, "Bob Chilcoat"
wrote:

It's my understanding that after Pappy Gunn had modified a B-25 for
straffing, with six 50 Cal Brownings in the nose and a 75mm field howitzer
under the floor of the cockpit, and had used it very successfully against
Japanese shipping, North American sent an engineer out to see what this
lunatic was doing. After looking over Gunn's field modification he just
shook his head and asked "Where the hell is the center of gravity?" Gunn
just shrugged and told him "Aw, we threw that out to save weight." The
engineer went home and North American started mass producing a properly
engineered variant of Gunn's cludge, the B-25G.

Pappy Gunn did not install any 75mm cannon's if I remember correctly.
He felt that the firepower of the .50 caliber machine guns was
adaquate, but more than that, he felt that it was necessary to
saturate the defenses with a dense volume of bullets to make them keep
their heads down while the bombers made their runs to the target.

The 75mm installation was done at the North American factory. Gunn
never liked it much. The fire rate was slow, it was inaccurate and
the recoil and flash were problematic. Most of the 75mm models had
their cannon removed from the airplane and replaced with more machine
guns once out to the war zone.

The skip bombers and the B-25 strafers actually developed side by
side, but independant of each concept. Initially, the skip bombing
technique was worked up by guys flying four engine bombers, mostly the
B-17. They practiced the run-in on a wreck out in Port Moresby's
harbor. Kenney always felt the bombers were too unwieldy for this
role and about the time a convoy of Japanese ships was detected
heading for New Guinea across the Bizmark Sea, he decided to attack it
using all his air forces.

Several B-17's did make attacks on the transports, but Australian
forces made attacks as well. The main thing though was that the B-25
strafers came into their own during this battle. They proved to be
extremely effective with their withering fire as they bore in at
wavetop height with all their machine guns blazing away. They'd
perfected the skip bombing technique by that time, which involved
dropping the bombs one by one in quick intervals, usually in a salvo
of four. This ensured that at least one would be at the right height
to penetrate the hull and detonate inside.

The Japanese literally had no counter for this tactic, which has got
to be one of the most successful field developed attack techniques of
WWII. So deadly was this technique that even the best destroyer
captains lost sleep pondering how to counter it, as nothing seemed to
work. See "Destroyer Captain" by Hara.

It must have been a truly terrifying situation to be in for the
Japanese as the B-25's normally attacked in pairs which limited the
maneuvering options of the target, no matter how fast and maneuverable
it was. The pilots split up and attacked from either side which split
the target's AA counterfire. But it did not split the attackers fire.

When the B-25's opened up, as many as 8 forward firing heavy machine
guns (ten if the top turret was swiveled to fire forward) poured an
absolute hail of bullets against the ship which caused even the
bravest sailer to flinch or duck for cover.

It wasn't all gravy for the B-25's though. Low level attacks like
this were extremely dangerous as any battle damage put the airplanes
into the ocean or jungle almost immediately. Many were lost.

Corky Scott

Corky

The Skip bombing carried over into the P-51's. The technique taught
was to drop short of the vessel and let the bomb
skip off the water into the side. Fuse was a short delay to let
aircraft clear the explosion. By dropping early if the pilot made a
mistake and actually dropped late, he would drop directly into the
side of the vessel which was a good hit.

One skip was ideal but I've see some dropped at high speed and skipped
several times before hitting. Remember all pilots felt that speed was
a life saver when being shot at in combat.

Big John

On Mon, 17 Nov 2003 14:39:42 GMT,
(Corky Scott) wrote:

On Fri, 14 Nov 2003 20:46:24 -0500, "Bob Chilcoat"
wrote:

It's my understanding that after Pappy Gunn had modified a B-25 for
straffing, with six 50 Cal Brownings in the nose and a 75mm field howitzer
under the floor of the cockpit, and had used it very successfully against
Japanese shipping, North American sent an engineer out to see what this
lunatic was doing. After looking over Gunn's field modification he just
shook his head and asked "Where the hell is the center of gravity?" Gunn
just shrugged and told him "Aw, we threw that out to save weight." The
engineer went home and North American started mass producing a properly
engineered variant of Gunn's cludge, the B-25G.

Pappy Gunn did not install any 75mm cannon's if I remember correctly.
He felt that the firepower of the .50 caliber machine guns was
adaquate, but more than that, he felt that it was necessary to
saturate the defenses with a dense volume of bullets to make them keep
their heads down while the bombers made their runs to the target.

The 75mm installation was done at the North American factory. Gunn
never liked it much. The fire rate was slow, it was inaccurate and
the recoil and flash were problematic. Most of the 75mm models had
their cannon removed from the airplane and replaced with more machine
guns once out to the war zone.

The skip bombers and the B-25 strafers actually developed side by
side, but independant of each concept. Initially, the skip bombing
technique was worked up by guys flying four engine bombers, mostly the
B-17. They practiced the run-in on a wreck out in Port Moresby's
harbor. Kenney always felt the bombers were too unwieldy for this
role and about the time a convoy of Japanese ships was detected
heading for New Guinea across the Bizmark Sea, he decided to attack it
using all his air forces.

Several B-17's did make attacks on the transports, but Australian
forces made attacks as well. The main thing though was that the B-25
strafers came into their own during this battle. They proved to be
extremely effective with their withering fire as they bore in at
wavetop height with all their machine guns blazing away. They'd
perfected the skip bombing technique by that time, which involved
dropping the bombs one by one in quick intervals, usually in a salvo
of four. This ensured that at least one would be at the right height
to penetrate the hull and detonate inside.

The Japanese literally had no counter for this tactic, which has got
to be one of the most successful field developed attack techniques of
WWII. So deadly was this technique that even the best destroyer
captains lost sleep pondering how to counter it, as nothing seemed to
work. See "Destroyer Captain" by Hara.

It must have been a truly terrifying situation to be in for the
Japanese as the B-25's normally attacked in pairs which limited the
maneuvering options of the target, no matter how fast and maneuverable
it was. The pilots split up and attacked from either side which split
the target's AA counterfire. But it did not split the attackers fire.

When the B-25's opened up, as many as 8 forward firing heavy machine
guns (ten if the top turret was swiveled to fire forward) poured an
absolute hail of bullets against the ship which caused even the
bravest sailer to flinch or duck for cover.

It wasn't all gravy for the B-25's though. Low level attacks like
this were extremely dangerous as any battle damage put the airplanes
into the ocean or jungle almost immediately. Many were lost.

Corky Scott

Great story, Thanks Big John and Corky Scott.

Man it must have sucked to be on either side during this attack. To go back
on topic, I guess letting this quantity of lead loose, it surely would
change the Forward CG experience.

Pat Thronson


"Big John" wrote in message
...
Corky

The Skip bombing carried over into the P-51's. The technique taught
was to drop short of the vessel and let the bomb
skip off the water into the side. Fuse was a short delay to let
aircraft clear the explosion. By dropping early if the pilot made a
mistake and actually dropped late, he would drop directly into the
side of the vessel which was a good hit.

One skip was ideal but I've see some dropped at high speed and skipped
several times before hitting. Remember all pilots felt that speed was
a life saver when being shot at in combat.

Big John

On Mon, 17 Nov 2003 14:39:42 GMT,
(Corky Scott) wrote:

On Fri, 14 Nov 2003 20:46:24 -0500, "Bob Chilcoat"
wrote:

It's my understanding that after Pappy Gunn had modified a B-25 for
straffing, with six 50 Cal Brownings in the nose and a 75mm field
howitzer
under the floor of the cockpit, and had used it very successfully
against
Japanese shipping, North American sent an engineer out to see what this
lunatic was doing. After looking over Gunn's field modification he just
shook his head and asked "Where the hell is the center of gravity?"
Gunn
just shrugged and told him "Aw, we threw that out to save weight." The
engineer went home and North American started mass producing a properly
engineered variant of Gunn's cludge, the B-25G.

Pappy Gunn did not install any 75mm cannon's if I remember correctly.
He felt that the firepower of the .50 caliber machine guns was
adaquate, but more than that, he felt that it was necessary to
saturate the defenses with a dense volume of bullets to make them keep
their heads down while the bombers made their runs to the target.

The 75mm installation was done at the North American factory. Gunn
never liked it much. The fire rate was slow, it was inaccurate and
the recoil and flash were problematic. Most of the 75mm models had
their cannon removed from the airplane and replaced with more machine
guns once out to the war zone.

The skip bombers and the B-25 strafers actually developed side by
side, but independant of each concept. Initially, the skip bombing
technique was worked up by guys flying four engine bombers, mostly the
B-17. They practiced the run-in on a wreck out in Port Moresby's
harbor. Kenney always felt the bombers were too unwieldy for this
role and about the time a convoy of Japanese ships was detected
heading for New Guinea across the Bizmark Sea, he decided to attack it
using all his air forces.

Several B-17's did make attacks on the transports, but Australian
forces made attacks as well. The main thing though was that the B-25
strafers came into their own during this battle. They proved to be
extremely effective with their withering fire as they bore in at
wavetop height with all their machine guns blazing away. They'd
perfected the skip bombing technique by that time, which involved
dropping the bombs one by one in quick intervals, usually in a salvo
of four. This ensured that at least one would be at the right height
to penetrate the hull and detonate inside.

The Japanese literally had no counter for this tactic, which has got
to be one of the most successful field developed attack techniques of
WWII. So deadly was this technique that even the best destroyer
captains lost sleep pondering how to counter it, as nothing seemed to
work. See "Destroyer Captain" by Hara.

It must have been a truly terrifying situation to be in for the
Japanese as the B-25's normally attacked in pairs which limited the
maneuvering options of the target, no matter how fast and maneuverable
it was. The pilots split up and attacked from either side which split
the target's AA counterfire. But it did not split the attackers fire.

When the B-25's opened up, as many as 8 forward firing heavy machine
guns (ten if the top turret was swiveled to fire forward) poured an
absolute hail of bullets against the ship which caused even the
bravest sailer to flinch or duck for cover.

It wasn't all gravy for the B-25's though. Low level attacks like
this were extremely dangerous as any battle damage put the airplanes
into the ocean or jungle almost immediately. Many were lost.

Corky Scott